Pneumatic logic circuit gas distributor - has alloy coated spool slidable in aluminium alloy body with oxidised bore surface

摘要

Pressurised gas distributor, esp. for pneumatic logic circuits, has a stationary sleeve with transverse inlet and outlet holes for gas. Inside the sleeve is a sliding valve provided with several peripheral annular grooves and an actuating rod so that gas can be directed to different logic circuits. The novelty is that neither grease nor a sealing ring are used between sleeve and valve which are thus in metal to metal contact; the sleeve is an Al alloy with its bore anodised to min. 550 Vickers hardness; the valve is an Al alloy with its working surfaces coated with Cu-In alloy which is diffused at 120-155 degrees C; the Cu-In is obtd. in an electroplating bath, contg. Cu+ and In3+ ions, aq. alkali hydroxide and other salts.